Internal combustion engine



Dec. 5, 1933. L. M. WOOLSON INTERNAL COMBUSTION ENGINE Filed April 2,1930 Patented Dec. 5, 1933 UNITED STATES PATENT OFFICE INTERNALCOMBUSTION ENGINE Application April .2, 1930. Serial. No. 440,89!

31 Claims.

ihis invention relates to internal combustion engines and moreparticularly to a method of operating a Diesel engine and to mechanismfor injecting liquid fuel into compressed air to form the combustionmixture.

In Diesel engines the combustion mixture is formed by the injection ofatomized liquid fuel of relatively low volatility, and there is requireda certain degree of fuel atomization and penetration thereby of thecompressed air in order to insure combustion. This requirement isnaturally more necessary when the fuel charge is of low volume, as whenstarting and idling, and because the pressure of the liquid fuel wheninjected into the compressed air must be at least such as to causeSllfiiClGIlt penetration or otherwise combustion will fail for lack ofproper intermingling of the mixture constituents.

With fuel mechanisms which are actuated through mechanism driven inaccordance with and by rotation of the crank shaft, the pressuredeveloped behind the fuel charges varies in accordance with the crankshaft speed, and in all of such mechanisms of which I am aware thestarting engine speed and usually the idling speed, at least during lowtemperature, are too low to produce the pressure in the injectionswhereby the fuel is atomized and penetrates the compressed air in amanner to insure combus- 30 tion. In order to overcome suchdifficulties, it has been proposed to apply heat to the cylinderstructure and to the air and the fuel previously to mixing, and whilesuch heat application is of some assistance, still it adds mechanism andcost and does not insure combustion. It is also well known that startingdimculties are in accordance with the temperature conditions, and thatthe application of heat without the proper atomization of the fuel andits penetration of the compressed 40 air charges does not insure easystarting even though the temperature is relatively high.

The starting mechanism which must be employed to rotate the crank shaftof a Diesel engine is necessarily so large as to be prohibitive if the45 crank shaft is to be turned fast enough to operate the fuel injectionmechanism in a manner which will develop a pressure behind the fuelcharge necessary to insure combustion. As a result, it is the commonpractice to use a small starter which will rotate the crank shaft slowlyand at the same time utilize auxiliary heat in some manner, but withsuch apparatus, starting difficulties are constantly prevalent. Ofcourse, the powerful starter would overcome the starting diflicultiesabove related, and there may be uses where the weight, cost and size ofsuch a starter would make no difference, but with small boats,aeroplanes, and motor-propelled apparatus such a starter is highlyimpractical.

An object of this invention is to provide a fuel injection mechanism forDiesel engines in which atomization of the fuel and its penetration intocompressed air will be suflicient to sustain combustion irrespective ofthe engine speed so that the fuel charge will be of a character suchthat it will ignite readily when the engine is turned over in starting.

Another object of my invention is to provide a method of operating aDiesel type of engine in which combustion will be assured when operatingat low speed.

An object of this invention is to provide fuel injection mechanism forDiesel engines in which the liquid fuel charges are introduced at apressure such that they will be adequately atomized and will penetratethe compressed air charges sufficiently to ignite during the compressionstroke during any speed of engine operation or regulation of the fuelcharge.

Another object of my invention is to provide an airless fuel injectiondevice for Diesel engines which will be actuated to discharge the liquidfuel into compressed air charges at a pressure, when the engine isoperating below a predetermined speed, which will support combustion.

Still another object of my invention is to provide a pressure fuelinjection device for Diesel engines in which there are two actuatingmechanisms for the pump plunger, one of which causes a faster strokethan the other and which is automatically brought into operativerelation when the engine crank shaft is below a predetermined rotationalspeed.

Another object of my invention is to provide a pressure fuel injectiondevice for Diesel engines in which a member is arranged to be actuatedby either one of two independent cams driven at different speeds by theengine, the faster speed cam being effective only below a predeterminedengine speed.

Another object of my invention is to provide a centrifugally controlledcam member which is associated with an engine in a manner such that itis effective to actuate a fuel injection device within a certain rangeof the engine speed.

A further object of my invention is to provide a radial engine with fuelinjector actuating means in which two cam members operating at differentspeeds can individually be effective and which the compartment 14.

will shield the injector actuating means from the other underpredetermined conditions.

These and other objects of the invention will appear from the followingdescription taken in connection with the drawing, which form a part ofthis specification, and in which:

Fig. 1 is a rear elevational view of a radial engine partially brokenaway to show the fuel injection mechanism;

Fig. 2 is a sectional view of the same taken on line 2-2 of Fig. 1;

Fig. 3 is a sectional view taken substantially line 33 of Fig. 2illustrating one of the cam structures.

Referring now to the drawing by characters of reference, illustratesgenerally a nine cylinder radial Diesel type of engineoperating upon afour-stroke cycle and designed particularly for use as the power plantfor an airship. There is a barrel type crank case 11 within which isarranged a transversely extending partition 12 which separates theconnecting rod containing compartment 13 from the accessory mechanismcompartment 14, and a rear end cover 15 closing Such rear cover isprovided with a plurality of apertures 16 through which suitablesecuring means can be arranged to fasten the engine upon a suitablesupport.

The cylinders 17 are air-cooled and include an integral head 18 uponwhich is secured an auxiliary head 19. In order that air may be drawninto the cylinders for the fuel charge, and burnt gas expelled from thecylinders, I provide a single passage 20 through the heads of eachcylinder which is in the form of a venturi extending tangentially of theinner wall of the cylinder and at an angle to the axis thereof. Suchpassages 20 are controlled by valves 21 which are each nor- ,mallyseated by springs 22 and held open by rock levers 23 which are actuatedby mechanisms ex tending through the housings 24 and terminating in rods25.

The crank shaft 26 extends axially through the .crank case and includesa single throw portion 27 upon which is associated a connecting rodassembly of the type usually employed with radial engines, there beingpistons 28 arranged to reciprocate in each of the cylinders andassociated with the connecting rod assembly in the usual transverselyextending fuel inlet ports 32.

manner.

Associated with each cylinder is an individual fuel injection deviceconsisting generally of a nozzle portion A and a pump portion Bpreferably formed as a unit assembly and secured to the side of thecylinder by the studs, 29. The

pump sections of the injecting devices include a barrel 33 having anaxially extending bore, in which a piston 31 is arranged to reciprocate,and The ports open into a housing formed by the attachment of aremovable casing 33 around the barrel, such casings being in opencommunication with a fuel feeding manifold consisting of a plurality ofsections 34. An overflow conduit-35 is connected to the uppermost fuelfeeding device for quantity of fuel charge which will be injectedthrough the nozzle into the compressed air in the associated cylinder,and the speed at which the plunger is operated will determine thepressure under which the fuel is injected into the compressed aircharges in the cylinder. It will be seen that the degree to which thefuel penetrates the compressed air charges and the degree of atomizationcaused by passing through the nozzle valve (not shown) will vary inaccordance with the pressure under which the fuel is injected into thecylinders by the plungers.

The fuel pump plungers 31 are operated by engine driven mechanism whichI will now describe. Arranged Within each of the pump barrels is a guidemember 36 to which the plunger is connected and a spring 37 is arrangedwithin the barrel to normally exert pressure against the guide member 36sumcient to cause its movement in a direction uncovering the inlet ports32 when the cams permit, so that after each injection stroke such springwill move the piston into a retracted position uncovering the fuel inletports 32 and allowing replenishing of the fuel. A sleeve 38 extendsthrough the crank case, adjacent each of the pump barrels, for thepurpose of guiding plunger actuating rods 39, such rods engaging theguide 36 and being reciprocably mounted in the sleeves. Links .0 areassociated with the rods 39 and also engage rock levers il, which arepivotally mounted upon shafts 42 extending transversely of thecompartment 14 and secured in the walls 12 and 15. The rock levers areprovidedwith a curved face 43 with which the links engage and upon wh chthey can be simultaneously and equally adjusted longitudinally byturning the ring 44, as the links 45 are connected to pins 45 and arepivoted to the links 40. The ring has slots 46 therein through whichstuds 47 secured to the wall 12 extend to retain the ring in position.Suitable rack and pinion mechanism 48 is associated with the ring 44 tobe operated by movement of the link 49 fixed to the shaft 50, therotation of which will cause rotation of the ring. The curved faces 43of the rocker members are related with the fuel pump actuating mechanismso that upon adjustment of the links e0 longitudinally of the rocklevers, the effective stroke of the plungers will be varied uponactuation of the rock levers. As shown in Fig. 1, the links 40 arerelated with the rock levers so that there will be a maximum pistonstroke after closing the fuel inlet ports 32 under which circumstancethe maximum quantity of fuel is delivered, but when the link 40 isadjusted toward the heel of the face 43, then the link stroke becomesslower and shorter, so that less fuel will be introduced into thecylinders. When the links 40 are at the right end of the rock leversillustrated, then the pump stroke is not sufiicient to close the inletports and consequently the cylinders will not receive any liquid fuel. I

Fixed to the crank shaft adjacent the partition wall 12 is a cam hubstructur consisting of members 51 and 52 which are secured together bythe bolts 53, there being a recess formed between such members andextending through a portion of the periphery thereof for the receptionof a pivoted arm 54 which is provided with a hub carried upon the bolt55 which extends through cam hub sections 51 and 52. The cam section 52is provided with an elongated hub which is keyed to the crank shaft andupon which a cam 56 is rotatably mounted, such cam being pro- R. P. M.

vided with four lobes 57 for actuating rock levers 58 with which thevalve actuating rods 25 are associated. The rock levers 58 are mountedparallel with the rock levers 41 and on the shafts 42. Four lobes 59 arealso arranged'on the cam 52 to actuate the rock levers 41, such lobesbeing in a plane intermediate the lobes 57 and the other cam hub. Thecam 56 is provided with an internal gear 60 which is rotated throughreduction gears 61, 62 and 63 driven by the crank shaft, and the cam 56is thus driven preferably at one-eighth crank shaft speed and in adirection reverse to that in which the crank shaft is rotating. 7 I

As heretofore stated, the arm 54 is pivoted upon the bolt 55 and isarranged to rock within a recess between the sections 51 and 52, therebeing a peripheral opening through which the lobe portion 64 can extend.The interior end of the arm 54 is in the form of a weight 65 and suchend of arm is anchored to the casing 51 by the coil spring 66. The coilspring, just mentioned, normally holds the cam member 54 in the positionshown in Fig. 3 but the tension thereof, which can be adjusted asdesired, must be overcome by centrifugal force when the crank shaft isrotating in order to move the lobe 64 into an ineffective positioninwardly of the recess as shown in dotted lines in Fig. 3. With the en-'gine illustrated, 1400 R. P. M. is calculated to sustain flight of anairship, and consequently I arrange the spring tension so thatcentrifugal force will move the cam lobe 64 out of operating positionwhen the crank shaft is rotating above 1400 It will be seen that therock levers 41 are provided with an extended portion 6'7 so that theycan be actuated by either the single lobe 64, or by the lobes 59 on thecam 56. When the engin is operating below 1400 R. P. M., the cam lobe 64will actuate the rock levers and as this cam is rotating at crankshaftspeed, the injection strokes transmitted to the plungers 31 will beseveral times faster than the stroke which would be transmitted by thecams 59 which are rotated at an eight to one speed reduction from thecrank shaft. When the engine is idling or being started, there Will be afast pump plunger stroke which will cause the fuel to be injected at amuch higher pressure than if the lobes 59 were causing the actuation,and thus when idling or starting, the pressure under which the fuel isinjected is always sufficient to cause a fine degree of atomization anda penetration of the air changes by the fuel charges such that the fuelintermingles and vaporizes in substantially the same manner as whenoperating under load thus permitting ease of starting and aiding ineflicient idling operation.

When the engine is operating at an R. P. M.

'of more than 1400, the cam lobe 64 moves inwardly and is in aninoperative position, whereupon the cam lobes 59 serve to cause theinjection strokes of the pump plungers, and at such speed the rate ofrotation of the cam 56 will be sufficient to cause a plunger movementfast enough to result in a pressure on the fuel which will cause thedesired atomizationofthe fuel and its penetration into the compressedair charges.

Having two cams rotating at different speeds for operating the fuelinjection mechanisms, it is necessary that provisions be made to causeone of the cams to be ineffective while the-other is effective, and thisI havearranged for automatically. As before related,the cam lobe-64 isautomatically effective or ineffective in accordance with apredetermined speed; the spring 66 causing the lobe to move intoeffective relation below a predetermined crank shaft R. P. M. andcentrifugal force causing the lobe to move within the cam hub and becomeineffective above a predetermined R. P. M. With such structure,therefore, it is still necessary that provision be made for causing thelobes 59 to be ineffective when the lobe 64 is effective, and this isaccomplished automatically also through the relation and form of the camlobes and their relation with the rock levers 41 together with thetiming of the cams relatively. The cam 56 rotates in a reverse directionto that of the crank shaft and at one eighth its speed while the othercam rotates with the crank shaf, and therefore the single lobe rotateseight times as fast as the lobes 59 and in a reverse direction. Uponeach two revolutions of the crank shaft, the cam 56 will be rotated aquarter turn and the lobes 59 will, when effective, have actuated eachof the rocker levers once in the cylinder sequence of 1'3-5 79-2-4-68.The lobe 64 rotates eight times as fast as the cam 56, and is fixed onthe crank shaft so that it will lift the rocker levers just in advanceof the lobes 59, the timing permitting this, and the lobes 59 willtherefore pass under the rocker levers ineffectively. The lands of thelobes 59 are made long so that the rocker levers will ride thereon afterthey have been raised by the lobe 64 until such lobe again passesthereunder, and in this manner the lobes 59 serve to allow the lobe 64to actuate only every other rocker lever in every revolution.

The cam lobe construction and arrangement is such, however, that therocker levers are allowed to ride onthe base circle of the cam 56between injection strokes in order to allow the pumps and nozzles tofill with oil to replace the 115 evacuated charge. I also provide thecam lobe end of the arm 54 with a gradually rising face 150 in orderthat stresses upon the pump mechanism caused by the shock of the contactof the lobe with the rocker levers 41 will be'reduced 130120 a minimum.It will be readily understood that the first part of the plungerinjection stroke is ineffective so that the gradual movement over alonger crank shaft angle, as caused by the face 150, will in no wayaffect the desired fast plunger injection stroke after the ports 32 areclosed.

The device herein described will automatically maintain a predeterminedminimum fuel atomization and penetration thereof into the compressed aircharges, even though the pressure 131] inducing, mechanism is operatedby the engine and also irrespective of the regulation of the fuelvolumeinjected. In this manner a Diesel engine can be readily started becausethe fuel mixtures will always be in a properly vaporized 135 andintermingled relation. It will be understood that other mechanism can beutilized to cause the minimum fuel pressure set forth, and that theinvention is not limited to the mechanism or the type of fuel injectiondevice illustrated.

When it is desired to start the engine,'an inertia or other conventionalform of starter (not shown) is applied to the crank shaft jaw 151 sothat the crank shaft is slowly rotated. Under such circumstances airwill be drawn into the 145 cylinderand compressed, the cam 64 willactuate the injection mechanism and cause a liquid fuel injection intothe compressed air, the compres-- sion of the air with the-fuel thereinis continued and then there is a power stroke after which the 15'scharge or burnt gases will be expelled. It will be understood that suchcycles occur in the cylinders in the order above mentioned. The cam 64continues to actuate the fuel injection mechanisms until centrifugalforce retracts it, at which engine speed the slower speed cam willpromote the requisite atomization of the fuel and its penetration intothe compressed air charges to sustain combustion. Thus at any enginespeed, the fuel is injected with suflicient force by engine operatedmechanism to insure a requisite atomization and penetration to insurecombustion, it being understood of course that several rotations of thecrank shaft by the starter may be required depending on the surroundingtemperature.

While I have herein described in some detail a specific embodiment of myinvention, what I deem to be new and advantageous and may specificallyclaim, I do not desire it to be understood that my invention is limitedto the exact details of the construction, as it will be apparent thatchanges may be made therein without departing from the spirit or scopeof myv invention.

What I claim is:

1. In an engine, a liquid fuel injection device including pressureproducingmeans, mechanism for actuating the pressure producing means, apair of engine operated cams rotated at different speeds and associatedto actuate the mechanism, and means actuated by centrifugal force formoving the faster cam into ineffective position above a predeterminedengine speed.

2. In an engine, a liquid fuel injection device including pressureproducing means, mechanism for operating the means, and a pair ofindependent cam means rotated at different speeds by the engine inregular paths for actuating the mechanism, one cam means having ashiftable lobe, said lobe shielding the other cam means from engagementwith the mechanism when in effective position and being ineffectivewhile the'other is effective.

3. In an engine, a liquid fuel injection device including a plunger,mechanism connected to cause reciprocation of the plunger, and a pair ofengine driven cams, each of said cams being associated with themechanism to individually cause complete injection strokes of theplunger, one of said cams having a pivoted lobe effective to operatesaid mechanism in a predetermined engine speed range, the other of saidcams being effective to operate said mechanism only in an engine speedrange in which the cam having the pivoted lobe is inefiective. r

4. In an engine, a liquid fuel injection device including a plunger,mechanism connected to cause reciprocation of the plunger, and a pair ofengine driven cams associated to individually actuate the mechanism andcause complete injection strokes of the plunger, only one of said camsbeing effective in each of two complementary portiens of the enginespeed range.

5. In an engine, a liquid fuel injection device including pressureproducing means, mechanism connected to cause reciprocation of thepressure producing means, a pair of cams arranged to individuallyactuate the mechanism to cause complete injection periods, and enginedriven means rotating said cams at different speeds, one of said cams,when effective, actuating said mechanism and preventing the mechanismbeing operated by the other cam.

6. In an engine, a liquid fuel injection device. including a plunger,mechanism connected to cause reciprocation of the plunger, and a pair ofengine operated cams arranged to individually actuate the mechanism andcause complete injection strokes of the plunger, said cams beingoperated in a timed relation so that when one is effective the other isshielded thereby from actuating the mechanism.

7 '1. In an engine, a liquid fuel injection device including a plunger,mechanism connected to causereciprocation of the plunger, a pair ofrotated cams arrangedto individually actuate the mechanism to causecomplete injection strokes of the plunger, and engine driven means forrotating the cams in opposite directions and at different speeds. I

8..In an engine, a liquid fuel injection device including pressureproducing means, mechanism connected to cause injection periods, a pairof rotatable cams arranged to individually actuate the mechanism andcause complete injections from the device, and engine driven means forrotating the cams at different speeds, the faster rotating cam beingeffective only during a low speed range of the engine and being timedrelative to the other cam during such speed range to maintain themechanism out of. position to be actuated by the slower speed cam.

9. In an engine, a liquid fuel injection device including an injectionproducing plunger, mechanism associated to reciprocate the plunger, andindividual engine driven actuating means each associated with themechanism to individually cause complete plunger injection strokes, saidmeans being operable automatically to change the speed of the plungerstroke relative to the engine speed. a

10. In an engine, a liquid fuel injection device including a plunger,mechanism associated to reciprocate the plunger, and a pair ofindependent engine driven means for individually actuating the mechanismto cause complete injection strokes of the plunger, one of said pair ofmeans operating at a faster speed than the other means.

11. In an engine, a liquid fuel injection device including a plunger,mechanism associated to reciprocate the plunger, and a pair ofindependent means driven at relatively different speeds by the engine,each of said means being associated to individually and completelyactuate the mechanism, only one of the means shielding the slower drivenmeans from engagement with the device at a time and the faster drivenmeans being effective in the slower speed range of the engine.

12. In an engine, a liquid fuel injection device including a plunger,mechanism associated to reciprocate the plunger, a pair of independentmeans driven at relatively different speeds by the engine associated toindividually and completely actuate the mechanism, only one of the meansbeing effective at a time, and automatic means for placing the fasterdriven means in effective relation with the mechanism during the slowerspeed range of the engine.

13. In an engine, a liquid fuel injection device including a plunger,mechanism associated to reciprocate the plunger, a pair of means drivenat relatively different speeds by the engine, each of said pair of meansbeing associated to independently and completely actuate the mechanismand arranged to be effective only one at a time, and 145 meansresponsive to centrifugal force for controlling the efiective andineffective relation of one of said means.

14. In an engine, a liquid fuel injection device including a plunger,mechanism associated to re- 1 .50

ciprocate the plunger, an engine'driven cam for actuating the mechanismto cause complete plunger injection strokes while the engine isperforming work, and automatically effective engine driven meansassociated with the mechanism to cause complete plunger injectionstrokes at a higher speed when the engine is idling than that whichwould be caused by the cam at similar engine speed.

15. In an engine, a liquid fuel injection device including a plunger,mechanism associated to reciprocate the plunger to apply pressure uponcharges injected thereby, engine operated means for operatingsaid'mechanism to produce complete high pressure plunger strokes, andanother engine actuated and controlled means for operating saidmechanism while the engine is idling to produce complete plungerinjection strokes of a higher pressure than that which would be producedby the first mentioned means under similar engine operating conditions.

16. In a Diesel engine, a liquid fuel inject on device includingmechanism associated to project fuel charges into compressed air, andseparate engine operated and controlled means each associated to actuatesaid mechanism, said separate means individually projecting completefuel charges different distances at any given engine speed into the aircharges, the means inducing the greater penetration of the air by thefuel charges relative to the engine speed being effective only below apredetermined engine speed.

17. In an engine, a liquid fuel injection device including a plunger,mechanism associated to reciprocate the plunger, a cam operated by theengine at crank shaft speed for actuating the mechanism to individuallycause complete plunger injection strokes, and another cam operated bythe engine at a speed which is a fraction of crank shaft speed toindividually cause complete plunger injection strokes, the fasteroperating cam being effective only below a predetermined R. P. M.

18. In an engine, a liquid fuel injection device including a plunger, apivoted lever having an extended contact boss, actuating mechanismintermediate the plunger and lever, a pair of cams for individuallydirectly contacting with the lever boss to cause complete plungerinjection strokes, said cams being driven by the engine at differentspeeds and effective one at a time.

19. In an engine, a liquid fuel injection device including mechanism forcausing fuel injection periods, a pair of cams effective one at a timeand rotated at different speeds and in opposite directions toindividually actuate the mechanism to cause complete fuel injections,and individual means driven by the engine for rotating said cams, thelobe arrangement of said cams being formed and timed in their rotationso that the effective cam will lift the mechanism and hold it out of thepath of the other cam.

20. In an engine, a liquid fuel injection device including a plunger,mechanism connected to cause reciprocation of the plunger, a pair ofseparate cams engageable with the mechanism to individually causecomplete plunger injection strokes, and means driven from the enginerotat ing the cams at different speeds, said cams being timed so thatone cam engages the mechanism ahead of the other and holds it lifteduntil the actuating portion of such other mechanism passes thereunder.

21. In an engine, a liquid fuel injection device including a plunger,mechanism connected to cause reciprocation of the plunger when actuated,

a pair of independent cams for operatingthe mechanism to individuallycause complete fuel injection plunger strokes, only one of said camsbeing effective at a time, means for rotating one of the cams at enginespeed, and means for rotating the other cam at several times less thanengine speed.

22. In a Diesel engine, a plurality of radially disposed cylinders, aplurality of devices cachincluding a plunger associated to projectliquid fuel charges directlyinto the cylinders, radially disposedplunger reciprocating mechanisms, and a pair of parallel camscooperating one at a time with the mechanisms to cause complete plungerinjection stroke and means driven by the engine for rotating said camsat different speeds.

23. In a Dieselengine, a, plurality of radially disposed cylinders, aliquid fuel injection device including a plunger associated with eachcylinder to move fuel charges at a high pressure therein, radiallydisposed mechanisms for reciprocating the plungers, a pair of enginerotated cams individually arranged to actuate the radial mechanisms tocause complete injection strokes of the plungers, one of said camshaving a single lobe and the other cam having plural lobes, said camsbeing in operative relation one at a time and the speed of rotation ofthe single lobe cam being a multiple of the rotation of the other camand effective only below a predetermined engine speed.

24. In a Diesel engine, a plurality of radially disposed cylinders, aliquid fuel injection device including a plun er associated with eachcylinder to move fuel therein, means for adjusting the plunger stroke tocontrol the fuel quantity in the charges, radially disposed mechanismfor reciprocating the plungers, and a pair of separate rotatable camsfor actuating the mechanisms to individually cause complete plungerstrokes, said cams being driven at different speeds and effective onlyone at a time.

25. In an internal combustion engine, a pressure device for injectingliquid fuel into compressed charges of air in the engine, a pair of camsindividually effective one at a time for completely actuating saidinjection device, said cams being driven by the engine at relativelydifferent speeds, and means operative to place either cam in effectiveactuating relation with the injection device.

26. In an internal combustion engine, a pressure device for injectingliquid fuel into compressed charges of air in the engine, a pair of camsindividually efiective one at a time for completely actuating saidinjection device, said cams being driven by the engine at relativelydifferent speeds, and automatic means operative to place one of the camsinto effective and ineffective actuating relation with the injectiondevice.

27. In an internal combustion engine, a pressure device for injectingliquid fuel into compressed charges of air in the engine, a pair of camsindividually effective one at a time for completely actuating saidinjection device, said cams in the compression stroke, and meansoperative to place either of said cams in efiective actuating relationwith the injection device.

29. In an internal combustion engine, a pressure device for injectingliquid fuel into compressed charges of air in the engine, a pair ofengine driven cams individually effective one at a. time to completelyactuate said injection device, said cams being timed differently in thecompression cycle, and automatic means selectively controlling the camrelation as to effectiveness in actuating the injection device.

30. In an engine, a liquid fuel injection device including a plunger,mechanism connected to actuate the plunger, a single lobe cam foractuating the mechanism to cause plunger injection strokes, means drivenfrom the engine for rotating the single lobe cam, a multiple lobe camfor actuating the mechanism to cause complete plunger injection strokes,and means driven from the engine for rotating the multiple lobe cam,said single lobe cam being operated at a multiple speed relative to thatat which the other cam is rotated.

31. In an engine, a liquid fuel injection device including a pressureproducing means, mechanism for actuating the pressure producing meansincluding a pair of cam means driven from an engine part at differentspeeds relatively and angularly disposed so that one normally leads andmasks the other from actuating the mechanism, and means for moving theleading cam means into an ineffective position unmasking the other cammeans.

LIONEL M. WOOLSON.

